This invention relates generally to door locks for self-cleaning ovens and more particularly to door locks wherein the act of closing the oven door positions a latch in a position to lock the door and a blocking device secures the latch in that position when a self-cleaning cycle is initiated.
A conventional gas or electric oven is subject to collecting deposits from whatever is placed in the oven to be cooked. Modern ovens are designed to self-clean upon demand by reducing these deposits to dust with high heat. This cleaning method is commonly known as pyrolytic cleaning. The high temperature used for pyrolytic cleaning poses a hazard if the oven door is opened during the cleaning cycle. To prevent this, an oven door lock is employed.
Many types of oven door locks have been provided that lock the oven door for a period sufficient to complete a pyrolytic cleaning cycle once initiated. Many of these door locks use electrical motors, electromechanical machines or manual manipulation of mechanisms to move a latch to a position in which the latch prevents the oven door from being opened during a self-cleaning cycle. Examples of such locks are disclosed in Thuleen et al., U.S. Pat. No. 4,082,078; McWilliams, III, U.S. Pat. No. 5,493,099; Smith, U.S. Pat. No. 6,302,098; Swartzell, U.S. Pat. No. 6,315,336; and Malone et al., U.S. Pat. No. 5,220,153.
Phillips, U.S. Pat. No. 6,079,756 discloses an oven door latch that is moved into a latched position by the closure of the oven door and that returns to an unlatched position upon opening of the door and is blocked in the latched position when a self-cleaning cycle is initiated while the door is closed. Phillips discloses using a plastic base plate mounted near the oven opening and using a solenoid to move a blocking member into a blocking position to prohibit movement of the latch from the latched position to the unlatched position during a self-cleaning cycle.
The disclosed oven lock mechanism uses the opening and closing of the oven door to position a latch member between a latched and an unlatched position and uses a relatively inexpensive motor to move a blocking member into a blocking position prohibiting the movement of the latch from the latched position to an unlatched position during a cleaning cycle. Typically, linear electromechanical actuators such as solenoids are more expensive than electrical motors and are often not as robust and reliable. Various embodiments of reliable and inexpensive motorized oven door locks are disclosed in this application.
According to one disclosed embodiment, an oven door lock mechanism for use with an oven having a door and a frame configured so that the door is adjacent the frame when the door is closed includes a latch, an actuator pin, a motor and a cam. The latch is supported above and coupled to the frame to rotate about a pivot axis and is rotatable between an unlatched and latched position. The latch includes a follower surface offset from the pivot axis and a latching member extending beyond the frame for interacting with the door. The actuator pin is movably supported by the frame and includes an outer end extending beyond the frame for engaging the oven door upon closure and a cam end engaging the follower surface of the latch for rotating the latch into the latched position wherein the door is adapted to be captured by the latch. When actuated, the motor drives a shaft to which the cam is mounted for rotation thereabout between a non-blocked position and a blocked position wherein the cam blocks movement of the latch from the latched position to the unlatched position. Movement of the cam between the non-blocked position and the blocked position is accomplished by rotation of the cam by 60 degrees.
An oven lock mechanism for use with an oven having a door and a frame surrounding a cooking chamber having an opening selectively closed by engagement of the door with the frame includes a mounting plate, a latch, an actuator pin, a blocker and an electromechanical actuator. The mounting plate is mounted to the frame. The latch is mounted to the mounting plate for movement about a pivot axis and is rotatable about the pivot axis between an unlatched and latched position. The latch includes a follower surface offset from the pivot axis. The actuator pin is movably supported by the mounting plate and includes an outer end extending beyond the mounting plate for engaging the oven door upon closure and a cam end engaging the follower surface for rotating the latch into the latched position wherein the door is adapted to be captured by the latch. The blocker is selectably rotatable into a blocking position when the latch is in a latched position for interfering with the rotation of the latch such that the latch is locked into the latched position for locking the oven door in a closed position. The electromechanical actuator is mounted to the mounting plate and rotates the blocker into the blocking position.
An oven lock mechanism for use with a self-cleaning oven having a door for selectively closing an opening of a cooking compartment surrounded by a frame and a compressible seal includes a mounting plate, a latch, a blockable member, an actuator pin, a blocker and a motor. The mounting plate is coupled to the frame near the oven compartment opening. The latch is pivotably mounted to the mounting plate about a pivot axis and is rotatable between an unlatched and latched position. The latch includes a follower surface offset from the pivot axis. The blockable member is mounted for movement relative to the mounting plate and is coupled to the latch so that when movement of the blockable member is blocked, movement of the latch from the latched to the unlatched position is inhibited. The actuator pin is movably supported by the mounting plate. The actuator pin includes an outer end extending beyond the mounting plate for engaging the oven door upon closure and a cam end engaging the follower surface for rotating the latch into the latched position wherein the door is adapted to be captured by the latch. The blocker is mounted for movement relative to the mounting plate to selectively block and unblock the blockable member. The motor is coupled to the mounting plate and when actuated moves the blocker.
Additional features and advantages of the present invention will become apparent to those skilled in the art upon consideration of the following detailed description of preferred embodiments exemplifying the best mode of carrying out the invention as presently perceived.